#include<stdio.h>
int main(int argc, char const *argv[])
{
    int a,i,b,n;
    printf("There are following friendly-numbers pair smaller than 3000:\n");
    for(a=1;a<3000;a++)
    {
        for(b=0,i=1;i<=a/2;i++)
            if(!(a%i))b+=i;
        for(n=0,i=1;i<=b/2;i++)
            if(!(b%i))n+=i;
        if(n==a&&a<b)
            printf("%4d..  %4d\n",a,b);
    }
    return 0;
}
